Answer and Explanation:
Platyhelminthes are mostly worm like organisms that are dorsoventrally flattened, meaning they look like a leaf and this is why they are coined names like the Tapeworm, Flatworm, Fluke and Planarian.
Most Platyhelminthes are parasites on other animals but only the Turbellarians are mostly non-parasitic. A few species are commensalists, or mutualists living with other larger organism.
They are classified into:
- Class Turbellaria
- Class Monogenea
- Class Trematoda
- Class Cestoda